Humanitarianism's Contested Culture in War Zones

Humanitarians are no longer simply seen as selfless angels. Their motivations and mastery, their principles and products are questioned from within and from without. Understanding the ongoing transformations in contemporary humanitarianism requires examining the nature and evolution of humanitarian culture away from an agreed culture of cooperation to a contested one of competition. The latter reflects militarization, politicization, and marketization. What is required is a learning culture for practitioners and a consequentialist ethics more oriented to responsible reflection than rapid reaction

Exact and approximate solutions for elastic interactions in a nematic liquid crystal

Anisotropic fluids appear in a diverse array of systems, from liquid-crystal displays to bacterial swarms, and are characterized by orientational order. Large colloidal particles immersed in such environments disturb the medium's orientational order, however, resulting in a stored elastic energy within the bulk. As a consequence, multiple immersed bodies interact at equilibrium through fluid-mediated forces and torques, which depend on the bodies' positions, orientations, and shapes. We provide the equilibrium configuration of a model nematic liquid crystal with multiple immersed bodies or inclusions in two-dimensions, as well as the associated body forces, torques, and surface tractions. A complex variables approach is taken which leans on previous work by Crowdy (2020) for describing solutions with multiply-connected domains. Free periods of a complex director field, which correspond to topological defect positioning and net topological charge, are determined numerically to minimize a global stored elastic energy, including a contribution of a weak (finite) anchoring strength on the body surfaces. Finally, a general, analytical description of two-body far-field interactions is provided, along with examples using two cylindrical inclusions of arbitrary position and size, and two triangles of arbitrary position and orientation.Comment: 33 pages, 6 figure

Dietary assimilation of cadmium associated with bacterial exopolymer sediment coatings by the estuarine amphipod \u3cem\u3eLeptocheirus plumulosus\u3c/em\u3e: effects of Cd concentration and salinity

Bacterial extracellular substances (also known as exopolysaccharides, or EPS) may serve as vectors for trophic transfer of metals in benthic systems because these ubiquitous sediment coatings can sorb high concentrations of toxic metals, and because many benthic invertebrates assimilate EPS sediment coatings upon ingestion. We conducted 3 sets of experiments to determine the assimilative bioavailability of EPS-associated Cd to the benthic amphipod Leptocheirus plumulosus as a function of Cd concentration and salinity. Bioavailability was measured as L. plumulosus Cd assimilation efficiency (AE) from EPS-coated silica (EPS●Si) and from uncoated silica (NC●Si) using modified pulse-chase methods with the gamma-emitting radioisotope 109Cd. Cd AE was significantly greater from NC●Si than from EPS●Si at 7.5%, but not at 2.5 or 25%. Overall, Cd AE from EPS●Si was between 15.1 and 21.5%. Because EPS●Si sorbed more Cd than NC●Si, EPS coatings magnified the amount of Cd amphipods accumulated at each salinity by up to a factor of 10. Salinity did not directly affect Cd AE from EPS●Si, but because Cd●EPS partitioning increased with decreasing salinity, amphipods accumulated more Cd from EPS at the lowest Cd●EPS incubation salinity (2.5%) than at higher salinities (7.5 and 25%). Finally, Cd concentration in EPS exhibited an inverse relationship with Cd AE at 2.5%, but not at 25%. Specifically, Cd AE was 12 times greater at 1 compared with 10µg Cd µg-1 EPS. Together, these results show that estuarine benthos can accumulate Cd from EPS sediment coatings, but that the degree to which this phenomenon occurs is dependent upon seawater salinity and Cd concentration in EPS

Microbial biopesticides for integrated crop management : an assessment of environmental and regulatory sustainability

Herbivorous insects and mites, plant diseases and weeds are major impediments to the production of food crops and are increasingly difficult to control with conventional chemicals. This paper focuses on microbial control agents with an emphasis on augmentation. There are marked differences in the availability of products in different countries which can be explained in terms of differences in their regulatory systems. Regulatory failure arises from the application of an inappropriate synthetic pesticides model. An understanding of regulatory innovation is necessary to overcome these problems. Two attempts at remedying regulatory failure in the UK and the Netherlands are assessed. Scientific advances can feed directly into the regulatory process and foster regulatory innovation

Long-term benthic foraminiferal culture: strategies for carbonate-system control and experimentation

Abstrac

Correction of misaligned slices in multi-slice cardiovascular magnetic resonance using slice-to-volume registration

A popular technique to reduce respiratory motion for cardiovascular magnetic resonance is to perform a multi-slice acquisition in which a patient holds their breath multiple times during the scan. The feasibility of rigid slice-to-volume registration to correct for misalignments of slice stacks in such images due to differing breath-hold positions is explored. Experimental results indicate that slice-to-volume registration can compensate for the typical misalignments expected. Correction of slice misalignment results in anatomically more correct images, as well as improved left ventricular volume measurements. The interstudy reproducibility has also been improved reducing the number of samples needed for cardiac MR studies

Exact quantum statistics for electronically nonadiabatic systems using continuous path variables

We derive an exact, continuous-variable path integral (PI) representation of the canonical partition function for electronically nonadiabatic systems. Utilizing the Stock-Thoss (ST) mapping for an N-level system, matrix elements of the Boltzmann operator are expressed in Cartesian coordinates for both the nuclear and electronic degrees of freedom. The PI discretization presented here properly constrains the electronic Cartesian coordinates to the physical subspace of the mapping. We numerically demonstrate that the resulting PI-ST representation is exact for the calculation of equilibrium properties of systems with coupled electronic and nuclear degrees of freedom. We further show that the PI-ST formulation provides a natural means to initialize semiclassical trajectories for the calculation of real-time thermal correlation functions, which is numerically demonstrated in applications to a series of nonadiabatic model systems.Comment: 10 pages, 6 figure